There are various websites to check the listing of the IP if it is blacklisted or not. The most preferred site to check the blacklisting of the IP is mxtoolbox.com
Browse this website mxtoolbo.com, and then click on “blacklist”. Once you are on the black list page, insert the IP address that you want to see if it is blacklisted. This will check various available blacklisted sites and see if your IP is black-listed or not. If it shows blacklisted “Status”, then contact the website where you can see the IP is blocked.
There are various ways to contact the black-listing sites, most often you do get option to contact the website where your IP is blocked.